SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4cf5b2376b4b2c95b83c8c9896aef5669db977939ce585aba056a03b9fd44e8f' 
  AND token = 'Y0xbJsqsn2PaJZd8W2qGwpnBLnYrjQcUMMg4+RmYT2s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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