SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc79a3d059d3e0fa9277dae1ccdf5a1977529dbadc6948f64fc1ff7ccc3ddeac' 
  AND token = 'KqmJLlvnEB1xEZ9Nysj0mTWuBpRgaU7f/6C+3+EKfII=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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