SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee283d6990893cc2e3c4a57fb82d5926e18eaa3e57b758e180252cf9a831e3c0' 
  AND token = 'uXApGcT2pQtVJFgCaMEtSeW2kACgJzk0HDchsz4PgrE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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