Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c6e51ffe9438954ff343a0c75d2ce5ab3e2491e997d126a4114f7856335ae958' 
  AND token = 'VFNfIk1UOwGpBBBduMFEmPiQvyOVU7LNuXCDRkjNXHU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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