SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e7a78834f1e8c9596ad3951139c9db628133d51cd4b3534c8a987e089b11b36' 
  AND token = '40+Vg1bJBVssf1LB7vBvlYnGOjqD7Ohxu8BL44F6zpk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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