SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7f7d73fe169a1ecf1c4f99469129543aa25870662d03bc85b3c8200fe7112d0' 
  AND token = 'Ur5gAAP+cE/9B+h+llYeoXKs1dIOkeu38O3hWAFvrAY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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