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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c375c634814192ff4f689aedf7499a81cc8ec1f3f3a1cb0b68ee356e0734ca27' 
  AND token = 'n7BsDyNQs8RmGusfNzLASIqzm3omsGA6SdEy0Eyl+zA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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