SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c76088b567dd25cfa7a3b4f650354d1321f951446f1cea5f88d35a4bc7451d71' 
  AND token = 'kkhsTZ+96y3nCA3g9HkvaAzjUwfXtZUw+h+vq4crR58=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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