SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c827d5ba3f2e455bbb5031a3032ebb1b08ddb6232f00df8fcceeaa29b88d914' 
  AND token = 'SwFFhimqKH0sSZ7BgulXeHNWV0fxgMSIJp8WGSfroas=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}