SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '597c5d2f3ed23a57eb68d4a9bb9088712bbcdd3e4f8d9299d290efac55f177eb' 
  AND token = '+bwhdHxDBBB7HiMjqYBFJztvCeLJBPrUfDrPJq2wqfQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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