SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfe7d46f7633e905f338fc0607e5d2602d45bb685a6e9137b24a8d9ee73ad486' 
  AND token = 'igoLTbN/AXW4zTHG5ZFCyRq8PXxCEXLl5dF2dGwLWxg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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