SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1bc7426b2fdfc9362893ac8375a8f2b0dcc595dbb26507f830b75edc372637b9' 
  AND token = 'ed9JtmlfhEZZBLy1aVeChO57vN0cyIzw3YNTZsPFsxM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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