SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46a6c4ed0370c0a70370d0bfac0dd3e1cb35a5a675810c5ccc1253f122e4fee6' 
  AND token = '7rEmmvvSGeFm9K82qiUqTwHKF3FFA4xfyC6dofjRehI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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