SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '54a188d13db7942a7e1f6c30a4da2dd4ff6a8c41b7e3984a87521fdf5673fb50' 
  AND token = 'fbyB9wLODe+YowzYDsvCuJ+kP6DX/3eJ8A3MaDn5fCQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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