SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c8efb9a189428dab48b659eea2cd2316b58107f5181d548e21364001cf45ba2f' 
  AND token = 'J6RmVKe2GG/pFoglI6g+N9js8YNPdnvhWT7Q8xfFR3E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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