SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd320899132bdb82a8e82165d9ee0742d43a6fe43d6086b03acd6f96b4e78fc8c' 
  AND token = 'JPb0O9X+E2fANnpdeHMZOal0PKkAqfJGrwlCQHVwafA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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