SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '09cc741dcd28fa019e1e6872b9551dc58288fb5eda31999b725a43c3045b428e' 
  AND token = '2/yvo+uQO4kpZN2lWQEXgd7fpdQp3PtbbgPV85m+zGw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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