SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34fded0065cf74e44f25d6ae33e7da72e1725113369a882ae92dd2edb620b791' 
  AND token = '4iEmSvtIaw/bUNLuGuph4echM+IAClQei34Uu61AVW4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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