SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3e9b9937a1510d89be41fe05601d88f8b892a9170374f98f53a165681e7892a0' 
  AND token = 'AqWvL+PKN6Nwr30k1aosFWgeqHeU/qyLElCQXn9w76o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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