SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d6aebeffe6d2d44c61e124fdc1fccda623fe03ca0974bab87cd6087fe231964' 
  AND token = 'B4n9FIN1JMgb83Kps7WXNfBbQeJwELPOg9oq2u98xFc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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