SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c218146db55ae09313673a4ffb7412baf5882e2091d15324c2d5bbfcd1eb2b48' 
  AND token = 'IKhGEr5drcaJ0jfU/aX7sCiaASi5AL29l8QZrehpMtE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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