SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '247b4566599dffa9abdca3e89c67e63060ed594575fc93817d2620f866bab374' 
  AND token = 'n3WpeGKpH8TdOmkZ4HPzcuzJlPY2IoJqsUaBvKrSSyw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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