SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a516c44beaef553dbd508153e75e676bd89b13571fdc3c1e78abd92c7698a8a6' 
  AND token = 'hvXjOUlag4yHGVGHdHYNHbj2VzCFP+tsASK9RRkTXow=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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