SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b7124d8e3f436192e67c76f3a2a7050d62cb9fdc3224be8ec66bb27f46afe476' 
  AND token = 'YNTWAUQZpiqnxikFUJ8n4FNKrYA/pevulJ7KF9Te530=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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