SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '42366fb13d99e264d7caf89a35edb6e0a55e6a35a1fbc282641edb1fddbb2fd7' 
  AND token = 'GaKierrKR+QAPPZmNN6QBWOeTccEcGOkmwCiEwDqQKc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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