SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b39322c913e3eaf249ddf15ee13abdd0bdaf0d704daf12b769c76d641e8cf45' 
  AND token = 'B0+ENkRGmqllqYo2iJKHBtDCVhS3jXNGpMhWcXyxaoY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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