SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb552eddcdb540ac247541975bc5e2b74d2994540147fd96d7ed75bc58bb2aaa' 
  AND token = 'gyCdLzMbEXOtPrM1zTubqCEU7+wDl/HqBbPdy24N17k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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