SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'dcedfe5a4b61a295962530fd70e616845340c41e998184f2afd8b8773a90dd55' 
  AND token = 'xnQVk53u5DskitVN6+9G1aZM0wBaqogI0+UuhvvtIiQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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