SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '904a89739c29df051dbb9b7d4b41a45ba0c5b5d834e7654fd0fdd11f7141e05c' 
  AND token = 'mvXFmjS6mq/WuE8MszlBsLhS/PeKfJydMVauBSTWJdM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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