SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a64054c3a361696604e3c44c8d3775578b1b311748432a43e910ad0ceed7130a' 
  AND token = 'G661d6rMw0kF9xOFpp/G/ieHN52+p4AWdaOQXAlAWaM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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