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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b2f8fb8b785ccabc1414ce3ba20222ff175b8d67a89ac3edc7ff2d5418f928a4' 
  AND token = 'kYkfQpyMbuTnyTU3WvqTS+6Pu/mEa+4gbthmV8LRUEk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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