SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7df5283a73b5c9908a59fcf584724628f8069c4d2ac71f9c80bc03accca56aa7' 
  AND token = 'bhE04PALClfjLhs4cCalXZ31+Gd07M7TICYtjxCfZ2s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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