SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a7e1b3a3f3e469dd45ae28e368267980395573e4c44b50d787d66bcea2a501d8' 
  AND token = 'WfguDjRzGUnux2uup6fHdVL929U7aOX1mGWwsK+Q4E8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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