SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '927762e6f3d94645f4d92cfcb1958519aadc41137b441d45d35ef806036aa482' 
  AND token = '6nAeMvogjzXhX66UGgh6w/zb7U4tQVxRRNP7FLxLScY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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