SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dfa096607705da2efec9be074b1ca24885ea57dc743878bbe273647e763bcb95' 
  AND token = '75G01txMWZAYApKeUL599w73IRbF0bH8o/a/eT3zJQ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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