SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4fdc1ec4ba33b07c774c4d48f315453541f116271a0811b1412a1302653fe935' 
  AND token = 'rFdfSfbB+9OQcNBk3S9N5z1Dc/czWXjlujuwf9lmWUY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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