SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d2cfbf492c28b14ca6fd6af3acc3f6be273aaa036ace4a9d059e0c15a9a97a1' 
  AND token = 'ZAcpsnN/hLgLb18t9U04yjdb5wnDhiKBsXBB4opHdzU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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