SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd304505105c0ca0cf64fd7d887f8c0994c7f362150d1e15519ba272ead16d8e0' 
  AND token = 'r0anjM7fnNGII7o6ahQjx/MEAiyk4pyaEshBPGlotl8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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