SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63acfef2b1d1d1ec178bfabe500d1d2b6410208cf22c7b353edba93893766dd2' 
  AND token = 'r/GO9qYITd/It5aZzVNd6pWo7Gmo2XhWM1qALSq+MXI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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