SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '430b08ea9ecccc797b21df3903a4cd7bf972678f0d2cdca824ea56267c684eca' 
  AND token = '4WT7ggpAOj6McsokbkIFnqrslvi+ro0jzlzkot9sdK8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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