SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2be153a76be95eacdf272838fed95831928ca5565a8e4571a2bf25918546343' 
  AND token = 'eGUWa/idoCuIrD/JHCRkYqv2jKcuSxWmyofib2YyQKM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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