SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ddb9e5d5c16a12731d2b703d505f780d9f035906d6212159b234c7a037cdfa1' 
  AND token = 'u0HCqGQ/eqvZ6Fih++s6ldquRdG2sfqewy2tjK9Ew7I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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