SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4154aac1aedb42c21c25306bf64ab3453b4f354a3454912409d616913f39f853' 
  AND token = 'Izq+qwgM5aXrcFEsyjHJxorFoBCMoR/zuMeIY/WxMLk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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