SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c89d5a064211653369a2eed5dd3591e3599d013973665fb147a01ba253542711' 
  AND token = '4JRyDTPD9FKUrz+RbJKOW5+q0cAfATkOj6mcHolrnvw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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