SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c43ba3f1193a312e35603a06203fb9f4ed7a246dc39efc967d797ca17f436b19' 
  AND token = 'wz2X4jUOPjdg9DsbWOCD0mwV385+gE+efARZmBQK0Nc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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