SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '905c3853dbec0df4b069289311394b8d331cdd2b127bc50e4be98f20a2c36244' 
  AND token = 'Qwl7FpvHKRX5j0Bz5W7QCmGvBlYmlNrASjKkhFsThUc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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