SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7714660bc1fb0d168137dfe872779305fe5eb03d1ea426741f5660df489091d5' 
  AND token = 'mYBHMIOdXMBpImggZTKsNDvMvtz96yRTJ+6YGPYvFIE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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