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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b1bf10ec1485eba40fc511b23ee9d4c0e4e408dab7fe07c574d082ad0b6d584e' 
  AND token = 'qUUYFn/WzMWIxj9aK6xW+u1xT3rUVkfP6DqTGCFzz/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}