SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd30d9ace71e76f76d5420e62ba23e0a2f3e22606ccafed348be2faef01019387' 
  AND token = '2cxibb2z40beznweGB39HXaxEYzFdN/+dS0wvTblpqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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