SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '919895824530f93bdc374dccea1dffa0f6f038a2f87bfed24634dcb4b0ae1308' 
  AND token = 'eYRAhWvZiIY1U4Wr7BnL4rGDp5pWM6OfZVXfjwqz+d0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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