SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73e576267150d8719fafc8cb623ea9f20d102455527dd7e4fc71782f7b36565a' 
  AND token = 'N0yfMzbXB8i/+xI3yMxWniWakpAiDjwqukJh0mltCU8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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