SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c532e374303cbbe404b0fdf6cdf22f2fbaa8e672bfa26b43a91be2370a9fd707' 
  AND token = 'ZeFjImxFNgSHTSWxMQE2smx67rtUMrUTp2/kUbibKyQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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