SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2577be8104295b256ad9e98086c01498419db1527901b24e976fa02387b850e8' 
  AND token = 'QoPPKGxXqz1L/xuZn7xTVBeR+Pfkzh4PW36zuoHK+cQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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