SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b939598a7f39c7b93f428b80832859a6cec2df37c644d3ac190edc8bfa0cad30' 
  AND token = 'zuP3JqZxgMO7PrXTUOmfKTS3wdLkSjPMxSHzPHxr3v0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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