SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '27614efc5113278271b96aa7f5d815cd5294ea03e10a2813aa9bccdfed47cffa' 
  AND token = 'rcvBKq6qEVYChzdWhUpkinNutExl+ZRuDduQYqJWOHs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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