SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92438e22525aac98a289a3881815bb693bca31828548cb19cdd225aec73490f3' 
  AND token = '1ffEqaXLwMHS3PJXbvCj1nuumVnWTfov9tZds070GN4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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