SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8816ae3c938bd8c9bcdce93ad21ba014ae059782e401ef8ad58764259f437e73' 
  AND token = 'P9L4c3cJb/XR5FRoWYTMgT0GdPEcdVQ9GAkHLIxZDlc=' 
  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"
    }
  }
}