SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f752f0290ec1e36435fcebd787427ca6b9e10992de007958858a74828dd03b7c' 
  AND token = 'aV4oiauw5pSXmgIYpYB8IZyPt//dudhmXcEKekzdjEE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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