SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7480fee9434e7dd99d7a86cfdba63db284e357a251a9f91bfe61bdbb04e6f484' 
  AND token = 'jK5yyXzmZVhsBemHiZETKM+GA7JZV6g3O/3FrR4AlP0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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