SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8253b3d13d3bd35f57eec07f051aa556821c0fab7924c1173a1522a141219c94' 
  AND token = '90zt5AGta4jBpQivJsasU2KWzvRF1rECSpyRZtzwgmU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}