SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc327d4226ba8ca041aa9a957002260bef93ebe4091328a815e4a99116ff3432' 
  AND token = 'EeNWoE458x2XUHn9O0yIPzVDQ8rkbeCzhG4apHJFDds=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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