SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '260fa9d1b78a3c846d9aaec916f90f860da57cec963e5f7d818efdd53619214a' 
  AND token = '60HpAfVNb19t5vjz2KmSTK+K1IdwWUgz+ZJqFnd+/Xk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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