SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b606412f2e1ae39534ca8172d81b987b4fbfebdc1ef80131ab1a2e366b952ea1' 
  AND token = 'VQNi8QwWbzsbqsWY92LkiEKxD17NnVfQisy8kNGW4vQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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