SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f5a9dd12ceb98f82e3925e904342d94085e325bae3fdb595e1a3f2fe848cc138' 
  AND token = 'HC07/zlOzA5pfVbxxpdtv4FdJ3iSknW/Y9JzNAMo1nk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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