SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '258946123cf988593dd327f0b74f3a91f3b148224af8cf820542730132cf5902' 
  AND token = 'SYbDQPpcZZunhTlRKgAhDKcSUWplGvfoxyuzHEVXT+k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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