SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '6955266ce205ff6a4b10852fe2d51059ab65b57a6d57672153fdc2f1ed161f86' 
  AND token = 'Dh3XLCL14ONgpb2wZUOLygkhSrfahMRODcCZ2JpJxgA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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