SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a4ae03bf6642bed609f4b7db13b09cfebe60858d23c42eb002f4ce4ae06191f' 
  AND token = 'Y5LUQk08EZxZ2jFGI9DSZMfOo4rtM4PGHCX3PDMda6Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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