SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09570939be1bf12bb1e32c9fcfdde1a4db614cfe1108d921233aebf96ec9cd42' 
  AND token = 'cTjdMz0u1aVE0rOO7qK4tB2ZWSMoDHvEU3ilp9ZU/Fs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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