SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f97c012724661cd03c60aab145a51bc9b808df35ec17aa38f187509c1cf70580' 
  AND token = 'Z6TcHJ34dfxIOyoGLiUv/IT8mreMFnsweT/knplAzfc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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