SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8632defe137bfad28e01e8cd396f88509b0c3f631a03609b05c95ee6e6835bd' 
  AND token = '7VLwjd3Tft8YuGjOnLsjmHxgTJHW/jQZKBq6XHv9tEM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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